Yorkshire today mounted a cheeky bid to take the crown for having Europe's cleanest beaches from the holder, Portugal.

A partnership including Yorkshire Water and Surfers against Sewage is planning to double the county's "excellent" ratings, bringing the EU's blue flag to all eight main resorts.

A five-year programme along 50 miles of largely sandy shoreline, from the artists' village of Staithes to Withernsea, on the crumbling coast of Holderness, will also clean up Europe's secondary category of rural beaches at coves such as Boggle Hole near Robin Hood's Bay.

The go-ahead follows Ofwat's approval of £110m funding for Yorkshire Water to upgrade the area's remaining below-par waste treatment works.

Gary Verity, the head of the region's tourist board, Welcome to Yorkshire, told the project launch in Scarborough: "We want to see those blue flags flying, to give us a higher concentration of excellent beaches than Portugal.

"The fact that we have this new joint effort by the water company, local councils, the National Farmers' Union and other organisations whose work has a direct impact on water quality is good news for Yorkshire."

The splendour of Yorkshire's beaches – with tracts of golden sand making the past fortunes of Scarborough, Filey and Bridlington – was marred in the last century by sewage and other pollution.

Children being forced to flee from a leak of raw sewage at Sandsend in the 1980s was the nadir, leading to high-profile campaigns by local groups such as the surfers and Sons of Neptune.

Graham Dixon, the production director of Yorkshire Water, said: "The way we operate our treatment works, sewers and overflows can have a major impact on the quality bathing waters, so securing this funding has given Yorkshire the best possible chance of achieving the new excellent standard. If we are to succeed, we must all do our bit."

David Dangerfield, the regional director of the Environment Agency, said the "wonderful, natural environment" of the North Sea coast needed constant work on finding and reducing pollution sources.

Jim Dillon, the chief executive of Scarborough borough council – which is part of the project – added: "Tourism is the lifeblood of our east coast resorts. Being able to boast the best beaches and bathing waters in Europe would be a major shot in the arm for the economy of the region."

Andy Cummins, the campaign director for Surfers Against Sewage, praised Yorkshire Water for aiming to reach the "excellent" standard rather than the easier "sufficient".

Blue flags now fly at the north bays in both Bridlington and Scarborough, as well as at Filey and the Captain Cook and Dracula port of Whitby. The clean-up is aimed at bringing Hornsea, Withernsea and the south beaches at Scarborough and Bridlington into the top bracket.

Withernsea's lighthouse is the likeliest place to house any trophy awarded to the local beach, with its display in memory of the actor Kay Kendall, who starred in Genevieve and 1950s Hollywood films. A Golden Globe winner, she was born in Withernsea and swam there as a child.

The number of blue flag beaches in England fell from 82 in 2008 to 71 last year, largely as a result of detritus and pollution caused by flooding and overwhelmed drainage.